The Ecological Insanity of Fish Farming

The Ecological Insanity of Fish Farming

As human populations continue to grow, more and more stress is placed upon ecological carrying capacity. One area where this is most evident is in marine eco-systems. There is simply not enough fish in the oceans to continue to feed the ever expanding populations of homo sapiens.

As wild populations of commercial fish are diminished, entrepreneurs developed the idea of domesticating the Atlantic salmon and raising it in enclosed pens. These "salmon farms" are presently proliferating along the coast of British Columbia, Chile, Scotland, New Zealand and Tasmania.

The first problem with this is that the Atlantic salmon is native only to one of these places - Scotland. The Atlantic salmon is also an exotic, an introduced alien species in the other marine environments.

This has caused more than a few problems, the first is that many of these salmon escape into these new environments and have been able to breed thus competing with native fish species for food and habitat. These alien species also spread diseases to native fish that have no resistance and again cannot compete with the domesticated fish that are fed anti-biotics and steroids in their feed.

And this fish food presents an even more serious problem. The salmon is a large and voracious predator. It eats fish and that fish has to come from somewhere. This has spawned an new industry to catch hundreds of thousands of tons of small fish to be converted into fish meal protein pellets for farm raised fish.

So what? Small fish are a small part of the 110 million tons of fish that people consume worldwide each year. We may as well feed the little ones to the big ones so that humans can continue to eat them.

As it is more than 50% of the fish taken from the oceans are fed to livestock making pigs, sheep, cows, and chickens the largest marine predators on the planet. Puffins are starving to death in the North Sea so that we can feed their primary food - the little sand eel to factory farmed chickens in Denmark.

These little fish feed on plankton and their primary competitors in the hunt for plankton are whales, whale sharks, and jellyfish. Whale and whale shark numbers have never really recovered and continued to be exploited.

But there is no market for jellyfish and jellyfish numbers are increasing and thanks to global warming and increased acidification of the seas, the numbers are accelerating. And what goes around comes around.

Recently Ireland's only salmon farm was wiped out when a massive drift of mauve stinger jellyfish destroyed a hundred thousand fish as they struggled to escape their enclosure that prevented escape but did not stop the invasion. They did not stand a chance and thrashed in agony from the stress of the stingers until they were 100% destroyed.

What this means is that we have set up a vicious cycle of marine ecological destruction. As wild populations of fish are diminished there will be more motivation to construct more and more salmon farms. These salmon farms will require more and more of a catch of wild small fish to provide fishmeal for the captive fish. This will mean fewer and fewer smaller fish meaning less competition for jellyfish and this coupled with increased acidic levels and global warming will mean escalating populations of jellyfish. These massive drifts of jellyfish will kill both wild and captive fish causing even more diminishment of fish species in the oceans and reducing the amount of fish protein available for human consumption.

Added to this is that projected increases in consumption due to continued human population growth will result in even more attempts to increase both the output of fish farms and wild fish exploitation. By 2050 the oceans could be fishless and populated by billions of floating jellyfish of various species and this will not be a healthy situation for all marine species and it will not be good news for humanity.

The Sea Shepherd Conservation Society has been criticized for advocating that people abstain from eating fish. Our views are considered radical and extreme. But what is more extreme than an ocean filled with jellyfish without fish?